Journal of Neuroscience, Vol 5, 3030-3038, Copyright © 1985 by Society for Neuroscience
Laminin and optic nerve regeneration in the goldfish
JM Hopkins, TS Ford-Holevinski, JP McCoy and BW Agranoff
Previous work from our laboratory had shown that goldfish retinal fragments
explanted onto a polylysine substratum 1 to 2 weeks following optic nerve
crush exhibit a striking clockwise pattern of neuritic outgrowth. In the
present study, however, when the basal lamina component laminin was used as
a substratum, neurites grew out as uncurved spokes, were less fasciculated,
and had an increased rate of elongation. When laminin was combined with
polylysine in the substratum, the degree of fasciculation and rate of
elongation were similar to those seen on laminin alone, whereas the
tendency for clockwise outgrowth was even more pronounced than that
observed with polylysine alone. These results suggest that regenerating
neurites have an affinity for laminin. Using an antibody to murine
Engelbreth-Holm- Swarm sarcoma laminin, which cross-reacted with basal
lamina in goldfish tissue sections, we studied the histochemical
distribution of laminin in the goldfish visual system. Immunoperoxidase
staining for laminin showed a characteristic scalloped pattern of staining
in cross- sections of optic nerve bundles. Following optic nerve crush, the
reaction product became much more diffuse and intense, especially distal to
the crush site. When the retinal ganglion cell bodies were eliminated by
removing the eye, the degenerating optic nerve stump still showed the
intensive staining. We interpret these results to indicate that optic nerve
glia are responsible in large part for the formation of laminin. Taken
together, these in vivo and in vitro findings suggest that laminin plays a
role in nerve regeneration in the goldfish central nervous system.